Hydraulic fracturing is a process commonly used to increase the flow of desirable fluids, such as oil and gas, from a portion of a subterranean formation. Hydraulic fracturing operations generally involve placing a viscous fracturing fluid into a subterranean formation or zone at a rate and pressure sufficient to cause the formation or zone to break down with the attendant production of one or more fractures—typically multiple fractures. The pressure required to induce fractures in rock at a given depth is known as the “fracture gradient.”
Nearly any fluid given enough volume and pressure can be used to fracture a subterranean formation. However, fracturing fluids generally include a viscosifying or gelling agent such as a cross-linked or uncross-linked polysaccharide material, and/or a viscoelastic surfactant, to affect the rheology by increasing viscosity of the fluid.
Typically, one or more fluids function to carry and transport proppant into the created fracture and form a proppant pack that keeps the fracture open once the pressure is released and the overburden is permitted to settle. As the viscous fracturing fluid leaks off into the formation, dehydrating the fluid, particulates (proppants and other particles) aggregate in proppant packs within the fracture. The proppant packs function to prevent the fracture from fully closing upon the release of pressure, forming conductive channels through which fluids may flow to (or from) the wellbore. The proppant pack is also designed to provide a higher permeability zone than the surrounding rock from which it is desired to produce hydrocarbons. The higher the permeability of the proppant pack, the greater is the potential for the production of hydrocarbons.
Accordingly, it is desired to provide compositions and methods which provide relatively high permeability proppant packs within fractures to enhance the production of hydrocarbons from the fractured subterranean formation.